Dual-Band and High-Efficiency Reflective Polarization Converter Based on Strip Grating

A structure acting as a linear polarization reflective rotator that can convert x- or y-polarized electromagnetic waves to cross-polarized waves in two bands is proposed. The unit cell consists of a metallic strip grating with 45° from the x-axis in the middle of the dual-layer substrate, and a bottom ground. The simulation shows the polarization conversion ratio of over 98% in the frequency range from 5.7 to 12.44 GHz and 23.75 to 30.65 GHz with fractional bandwidths of 74.3% and 25.4%. The reason of dual-band polarization-converting function is explained by the equivalent circuit model of two orthogonal components. The fullwave simulation and equivalent circuit model results are all in agreement with the entire frequency regions.